A bio-based 1,3-propanediol (BioPDO) product derived from corn sugar by bioprocess has been
considered as a green alternative to regular petroleum-derived glycol products e.g., propylene glycol
(PG), for heat transfer fluid and antifreeze applications. Electrochemical and glassware immersion
(ASTM D1384) corrosion tests were performed to evaluate corrosion performance of various metals in
the BioPDO aqueous (50%) solutions, uninhibited and inhibited with addition of a phosphate based
corrosion inhibitor. The results showed that the corrosion performances of the uninhibited and inhibited
BioPDO solutions were very similar and comparative to those of PG solutions formulated and tested at
the same conditions. That is, both the inhibited BioPDO and PG solutions displayed excellent corrosion
performances for all the metals tested, and yet both the uninhibited BioPDO and PG solutions were
corrosive to ferrous metals and some nonferrous metals. The glassware immersion testing method was
considered better than electrochemical testing method used for evaluation of the effectiveness of the
corrosion inhibitor over a long appearance period.